CN113715899A

CN113715899A - Steering system

Info

Publication number: CN113715899A
Application number: CN202110564797.8A
Authority: CN
Inventors: F·舒伯特; T·波兹尔
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2020-05-25
Filing date: 2021-05-24
Publication date: 2021-11-30
Also published as: DE102020206429A1; US11866105B2; US20210362772A1

Abstract

The invention relates to a steering system having at least one steering rod and a steering motor, wherein the steering motor acts on the steering rod via a ball screw transmission. The drive nut is rotatably mounted in the housing by means of a bearing assembly. Furthermore, the drive gear of the traction means drive can be connected in a tilting-proof manner to the inner ring of the rotary bearing of the bearing assembly, via which the drive power of the steering motor can be transmitted to the drive nut. Furthermore, it is provided that the transmission nut is mounted on the transmission gear so as to be pivotable about a pivot axis that is oriented perpendicularly to the longitudinal axis of the steering rod. For this purpose, the transmission nut has a curved joint section which interacts with a curved joint section which is formed at least in part by the transmission gear to form a pivot bearing. The elastically deformable spring ring arranged between the hinge sections ensures play-free properties of the pivot joint.

Description

Steering system

Technical Field

The invention relates to a steering system having a steering rod which is mounted in a housing so as to be axially displaceable in the longitudinal direction and having a steering motor which acts on the steering rod via a ball screw drive, for which purpose the steering rod, in at least one section, forms a ball screw which interacts with a drive nut which can be driven by the steering motor, wherein the drive nut is mounted rotatably in the housing by means of a bearing assembly.

Background

Such a steering system is known from DE 102014006469B 3. In this steering system, the drive nut is mounted in a non-movable manner in a retaining ring which is formed in an outwardly convex curved manner to form a pivot bearing and is mounted in the inner ring of the rotary bearing. The inner ring of the rotary bearing is correspondingly concavely curved on the inside. Furthermore, the inner ring of the rotary bearing is connected to the belt pulley in a rotationally fixed manner.

The german patent application, which was not published hitherto, with the document number DE102019201933.1 likewise describes a steering system of the type mentioned at the outset. The steering system comprises in particular a steering rod mounted in a housing so as to be longitudinally displaceable, and a steering motor which acts on the steering rod via a ball screw drive, for which purpose the steering rod forms a ball screw which interacts via a spherical transmission element with a drive nut which can be driven by the steering motor, wherein the drive nut is mounted rotatably in the housing by means of a bearing assembly. Furthermore, a transmission gear wheel of a traction means transmission, via which the drive power of the steering motor can be transmitted to a transmission nut, is connected in a tilt-proof manner to the inner ring of the rotary bearing of the bearing assembly, wherein the transmission nut is mounted on the transmission gear wheel so as to be pivotable about a pivot axis oriented perpendicularly to the longitudinal axis of the steering rod. For this purpose, the drive nut has a curved joint section which, together with the curved joint section of the drive gear, forms a pivot bearing. Between the hinge sections, a sliding bearing layer can be arranged, whereby a movability of the pivot bearing with as low friction as possible is to be achieved. The sliding bearing layer can be formed here in the form of a separate component made of plastic. Furthermore, the movable first partial section of the articulation section of the transmission gear is elastically pressed by means of a preloaded loading device in the direction of the second partial section of the articulation section of the transmission gear, as a result of which a largely play-free nature of the pivot bearing is formed. The loading device comprises two ring elements, each of which has an end face which is designed as a bevel, at least in sections, wherein the bevels of the two ring elements are in contact with one another, and wherein the ring elements are loaded by means of a plurality of prestressed spring elements in order to execute a relative rotation. By means of such a loading device, a relatively large readjustment stroke (nachsellweg) for the first partial section of the articulation section of the transmission gear can be achieved at the same time with a relatively small dimension in the axial direction of the loading device. Such a relatively large readjustment stroke may be necessary because the sliding bearing layer, which is designed as a separate component made of plastic and is arranged between the articulation section of the transmission gear and the transmission nut, is subject to relatively large plastic deformations due to creep (Setzen) of the plastic during the service life of the steering system, which should be compensated for to a corresponding extent by the loading device. A disadvantage of such a steering system is therefore the relatively large constructional complexity which is associated in particular with the provision of a relatively complex loading device.

Disclosure of Invention

The object of the present invention is to provide a steering system which is functionally advantageous and at the same time can be produced simply and cost-effectively.

This object is achieved by means of a steering system according to claim 1. Advantageous embodiments of the steering system according to the invention and methods for assembling such a steering system are the subject matter of further claims and/or are derived from the following description of the invention.

According to the invention, a steering system is provided with at least one steering rod mounted in a housing so as to be movable in the longitudinal direction and a steering motor, wherein the steering motor acts on the steering rod via a ball screw transmission, for which purpose the steering rod in at least one section forms a ball circulation thread which interacts via a spherical transmission element with a transmission nut which can be driven by the (preferably electric, possibly also hydraulic) steering motor. The drive nut is rotatably mounted in the housing by means of a bearing assembly. Furthermore, a transmission gear of the traction means transmission, for example of the toothed belt transmission, is connected in a tilting-proof and preferably also torsion-proof manner to an inner ring of a rotary bearing of the bearing assembly, by means of which the drive power of the steering motor can be transmitted to the drive nut, which rotary bearing is preferably designed in the form of a rolling bearing. In this context, "tilt-resistant" means that the tilting of the transmission gear about any tilting axis or about each tilting axis lying perpendicular to its longitudinal axis is transmitted to the inner ring of the rotary bearing. Furthermore, it is provided that the transmission nut is mounted on the transmission gear so as to be pivotable about (in particular about each) pivot axis, which is oriented perpendicularly to the longitudinal axis of the steering rod. For this purpose, the drive nut has a curved, preferably partially spherical and/or convexly curved articulation section which interacts with a curved, preferably partially spherical and/or concavely curved articulation section which is formed at least partially, if appropriate completely, by the drive gear in order to form the pivot bearing. In order to achieve a maximum or at least sufficient play-free behavior of the pivot joint, at least one elastically deformable spring ring, in particular an elastomer ring, is arranged between the joint sections.

The drive nut and/or the drive gear are preferably completely, but at least in the region of the bent hinge section, made of metal, in particular of steel and/or aluminum, in order to ensure the highest possible load capacity and in particular also the minimum creep behavior.

Due to the design of the steering gear, in which the pivot bearing ensuring the pivotability of the drive nut is formed on the drive gear, rather than on the pivot bearing itself, a decoupling of the drive nut, which pivots due to a corresponding bending load of the steering rod, from the pivot bearing can be achieved, as a result of which a number of advantages can be achieved. One of these advantages consists in the automatic elimination of the play of the swivel bearing, whereby undesirable noise generation can be avoided or reduced. The reason for this automatic elimination of the play of the pivot bearing is that, in conjunction with the decoupling of the pivot movement of the pivot bearing from the drive nut, which is additionally achieved by the design according to the invention of the steering system, the drive gear is connected in a tilt-resistant manner to the inner ring of the pivot bearing, which decoupling is achieved by the formation of the pivot bearing in the region of the drive gear. The bearing play and in particular the axial play of the rotary bearing can be eliminated by the drag load of the drag means drive acting on the drive gear in such a way that it causes a slight tilting of the inner ring of the rotary bearing and is decoupled from the pivoting movement of the drive nut.

Furthermore, due to the configuration of the steering system according to the invention, a decoupling of the drive nut from the traction load of the drive gear of the traction means drive can be achieved, which has a positive effect on the relative movement of the ball screw drive in terms of achieving the best possible and in particular also maintaining the same frictional resistance.

At the same time, despite these achievable advantages, the steering system according to the invention can also have a relatively simple structural and therefore also robust and cost-effective construction. In the steering system according to the invention, the play in the pivot joint, which can form at least during the service life of the steering system due to wear, is compensated for by an elastically deformed spring ring which presses the joint sections directly or indirectly against one another at least in sections without play.

According to a preferred embodiment of the steering system according to the invention, it can be provided that a sliding bearing layer is arranged between the joint sections. The plain bearing layer can preferably be designed as a separate component and/or be made of plastic (plastic, for example comprising PTFE), which enables a simple and cost-effective manufacturability while achieving a good functionality with regard to the lowest possible frictional resistance of the pivot bearing. Alternatively, however, it is also possible to provide at least one of the joint sections with a sliding coating and/or to arrange a lubricant, in particular a pasty lubricant, for example a grease, between the joint sections in order to form the sliding bearing layer. A "sliding coating" is understood here to mean a coating which is arranged fixedly on the surface of the base body of the transmission gear or of the transmission nut and which consists of a material which differs from the material of the base body. The material may be, in particular, a sliding material which, in combination with the material used to form the mating contact surfaces, has a relatively low coefficient of friction and, in particular, has a coefficient of friction which is as low as possible. The sliding coating which is advantageous for the intended application can, if appropriate, consist essentially of Polyoxymethylene (POM) and, if appropriate, additionally of Polytetrafluoroethylene (PTFE).

If the material of the sliding bearing layer has outstanding creep properties under load, the increased play in the pivot joint resulting from this creep can in turn be compensated by the elastically deformed spring ring, which, if necessary, leads to a correspondingly large dimensioning of the spring ring with respect to the elastic restoring action and thus, in particular, also with respect to the cross-sectional dimension.

In order to avoid as far as possible any play of the pivot bearing that becomes large over the service life of the steering system as a result of creep of the material of the plain bearing layer, provision may preferably be made for such creep to be at least partially anticipated in the context of the installation of the steering system. To this end, the method according to the invention for assembling a corresponding steering system can provide that the width of the joint gap between the joint sections and accommodating the plain bearing layer is adjusted, which width (in at least one section, preferably overall) is smaller than the thickness of the plain bearing layer in the unloaded state.

Since in the steering system according to the invention at least sufficient play-free properties of the pivot ring can be ensured by the spring ring, a complicated loading device as described in german patent application DE102019201933.1 can be dispensed with, as a result of which a simple and cost-effective structural design of the steering system is obtained. In particular, it is also possible to design the first partial section of the articulation section of the transmission gear and the main body of the transmission gear having the functional surface (directly) contacting the traction means of the traction means transmission in one piece, which enables particularly simple and cost-effective manufacturability.

In a preferred embodiment of the steering system according to the invention, it can be provided that the transmission gear is designed as a transmission ring gear and that the articulation section of the transmission nut is arranged at least partially, if necessary completely, inside the transmission gear. In this way, a particularly compact design of the steering system can be achieved, at least with regard to the extent along the longitudinal axis of the steering rod.

In order to achieve a direct transmission of the drive power of the steering motor from the transmission gear, which is part of the traction means transmission, to the transmission nut, it can be provided according to a preferred embodiment of the steering system according to the invention that the transmission gear is connected to the transmission nut in a rotationally fixed manner, i.e. in a torque-transmitting manner, by means of a coupling (kupplong). The coupling is designed such that it ensures pivotability of the pivot joint despite the rotationally fixed connection.

A coupling which can advantageously meet these requirements has a toothing of the transmission gear, preferably an internal toothing (in particular in the preferred embodiment of the transmission gear preferably as a transmission ring gear), and a toothing of the transmission nut, preferably an external toothing, which cooperate in such a way as to engage into one another in order to transmit torque. The teeth of these teeth can be oriented here preferably parallel to the longitudinal axis of the steering rod. Furthermore, the teeth may preferably have a curved-running tooth head and/or a curved-design tooth flank, so that the coupling may then be designed in the form of a so-called curved-tooth coupling. Since the teeth of the transmission gear and of the transmission nut engaging into one another can be part of the pivot joint, it can preferably be provided that a sliding bearing layer is likewise arranged between these teeth. This ensures the lowest possible frictional movability of the pivot joint. In this case, the sliding bearing layer can preferably also be a separate component and/or be made of plastic and particularly preferably be configured in one piece and material-matched to the sliding bearing layer arranged at least in one section between the hinge sections. In addition or alternatively, it can also be provided that at least one of the teeth is provided (at least in sections) with a sliding coating and/or that a lubricant is arranged between the teeth engaging into one another.

The integration of the coupling piece, which is particularly advantageous in terms of dimensions but also in terms of functionality, can be achieved in that the coupling piece is arranged (preferably centrally) between the first partial section and the second partial section of the articulation section of the drive nut and/or between the first partial section and the second partial section of the articulation section of the drive gear.

According to a preferred embodiment of the steering system according to the invention, it can furthermore be provided that the drive nut is arranged with a defined radial play (i.e. with a defined spacing over the entire circumference of the drive nut) within the inner ring of the rotary bearing. The radial play can preferably be selected to be so large that contact between the drive nut and the inner ring is avoided in all desired tilting positions between the components, which occur during normal operation of the steering system. The partial arrangement of the transmission nut in the rotary bearing enables a compact design of the steering gear of the steering system, while at the same time a relatively large length of the transmission nut is achieved, which in turn has a favorable effect on the magnitude of the drive power that can be transmitted by the ball screw drive. In this case, despite this arrangement, the radial play ensures decoupling of the rotary bearing from the pivoting movement of the drive nut.

The (preferably single) rotary bearing of the bearing arrangement of the steering system according to the invention can advantageously be a single-row ball bearing, in particular a four-point bearing (vierpunktilager) (for example according to DIN 628), which, although suitable for transmitting relatively high axial forces, enables a relatively cost-effective design of the steering system.

The tilting-resistant and preferably also torsion-resistant connection of the transmission gear to the inner ring of the rotary bearing can be achieved, on the one hand, by the fact that it is formed in one piece, that is to say, as one and the same component. It is also possible to design the components as separate components and to connect them to one another accordingly.

The steering system according to the invention can preferably be designed as a power-assisted steering system and can thus be implemented such that a manually generated steering torque, which is transmitted to the steering gear via a steering handle (e.g. a steering wheel) and preferably with the steering column connected in between, can be superimposed by the steering torque generated by the steering motor in order to reduce the magnitude (if necessary also to zero) of the steering torque required for steering and to be generated manually. The steering gear can in particular comprise a steering pinion which interacts with a toothing formed by the steering rod in a section. On the other hand, the steering system can also be constructed such that the steering motor always provides the entire drive power required for steering.

The invention also relates to a motor vehicle, in particular a wheel-based motor vehicle free from track constraints, preferably a passenger car or a truck, having a steering system according to the invention.

Drawings

The invention is further elucidated below by means of an embodiment shown in the drawing. Shown in the attached drawings:

fig. 1 shows a section of a steering system according to the invention in longitudinal section, and

fig. 2 shows a ball screw drive of the steering system according to fig. 1.

Detailed Description

Fig. 1 shows a section of a steering system according to the invention, which is designed as a power steering system. The steering system comprises a multi-part, substantially tubular housing 1, in the interior of which a steering rod 2 is mounted so as to be movable longitudinally, i.e. along its longitudinal axis 3. The steering rod 2 is connected at its two ends to ball joints (not shown), which are in turn used for connection to wheel steering levers (not shown). The wheel steering rod converts the longitudinal axial movement of the steering rod 2 into a pivoting of the steered wheels (not shown) of the motor vehicle.

The longitudinal axial movement of the steering rod 2 is caused on the one hand by a rotary movement of a steering handle (not shown), in particular a steering wheel, of the motor vehicle, wherein this rotary movement of the steering handle is transmitted to a steering pinion (not shown) via a steering column (not shown). For this purpose, the steering pinion can interact with a toothing (not shown) of the steering rod 2 in order to convert a rotary movement of the steering pinion into a translational movement of the steering rod 2 along its longitudinal axis 3.

Furthermore, a longitudinal axial movement of the steering rod 2 can be brought about by generating an auxiliary steering torque by means of the steering motor 5, which is electrically designed in the exemplary embodiment. For this purpose, the drive power of the steering motor 5 is also transmitted to the steering rod 2 by means of a ball screw drive 6, for which purpose the steering rod 2 in one section forms a ball circulation thread 7 with a partially circular thread groove cross section. A plurality of spherical transmission elements 8 are arranged inside the section of the ball circulation thread 7 that is variable in the direction of rotation, said transmission elements being accommodated in addition inside running grooves (laufriclen) of the ball circulation thread, which are likewise of partially circular cross section, and which are formed on the inside of the base body 9 of the drive nut 4 of the ball screw drive 6. The drive nut 4 of the ball screw drive 6 is rotatable as a result of being mounted in a bearing assembly, but at the same time is integrated into the housing 1 substantially fixedly or immovably with respect to its longitudinal axial direction. The rotary drive of the drive nut 4 is effected with the intermediate connection of a further gear stage in the form of a traction means gear, which in the exemplary embodiment shown is designed as a belt drive, for which purpose the drive nut 4 is connected in a rotationally fixed or torque-transmitting manner to a first drive gear (pulley) 11. The first transmission gear 11 is partially wound by a belt 12, here in the form of a toothed belt, wherein the belt 12 is additionally guided by a second transmission gear 13, which is connected in a rotationally fixed manner to a driven shaft 14 of the steering motor 5. Therefore, the rotational movement of the driven shaft 14 of the steering motor 5 is transmitted via the belt transmission to the transmission nut 4 of the ball screw transmission 6, wherein a reduction in the rotational speed occurs (transmission ratio i > 1). This rotational movement of the drive nut 4 is then converted into a translational movement of the steering rod 2.

Since significant transverse forces can act on the end of the steering rod 2 via the wheel steering rod when converting a longitudinal axial movement of the steering rod 2 into a pivoting movement of the wheels of the motor vehicle, a relatively large potential for a bending deflection of the end of the steering rod 2 arises in combination with a relatively large spacing between the end of the steering rod 2 and the drive nut 4 which causes a radial support of the steering rod 2. This bending deflection can optionally be kept as small as possible by additionally mounting the steering rod 2 in the vicinity of the longitudinal axial end of the housing 1 and thus radially supporting it. However, the associated tilting or tilting of the steering rod 2 in the region of the drive nut 4 of the ball screw drive 6 cannot always be avoided.

In order to ensure the lowest possible friction operation of the ball screw drive 6 even in the case of such a tilting position of the steering rod 2 in the region of the drive nut 4, the drive nut 4 should likewise be tiltable into the respective tilting position. At the same time, the longitudinal and transverse forces exerted on the steering rod 2 must also be supported by the mounting of the drive nut 4 in the interior of the housing 1. For this purpose, not only should the bearing assembly be supported as free as possible in the longitudinal axial direction and in the radial direction inside the housing 1, but the drive nut 4 should also be accommodated correspondingly free of play inside the bearing assembly.

For this purpose, the bearing assembly comprises a rotary bearing 15 in the form of a single-row four-point bearing (according to DIN 628), which comprises an outer ring 17 in addition to an inner ring 16, and also a plurality of rolling elements 18 in the form of balls arranged between the bearing rings 16, 17 and a rolling element cage 19. The outer ring 17 of the rotary bearing 15 is directly supported in the bearing receptacle of the housing 1 and is fixed axially there. The inner ring 16 of the rotary bearing 15 projects with one of its axial end sections beyond the outer ring 17 and is connected with this end section in a tilt-proof manner to the first transmission gear 11. The anti-tipping connection is realized by means of a retaining ring 21 which engages in a circumferential groove of the inner ring 16 of the rotary bearing 15 and in a circumferential groove of the base body 20 of the first transmission gear 11, respectively. However, in addition or alternatively, other types of positive-fit and/or non-positive connections, such as screw connections and/or material-fit connections, for example by welding or soldering, may also be provided.

The bearing assembly further comprises a pivot bearing for pivotally supporting the drive nut 4 and the first drive gear 11 to each other. The pivot bearing is formed by the drive nut 4 cooperating with the first drive gear 11 and the inner ring 16 of the rotary bearing 15. For this purpose, the basic body 20 of the first transmission gear 11 is designed as a ring gear, wherein two partial sections 23, 24 of a hinge section 22 extending in a partially spherical and concavely curved manner are arranged on the inner side of the basic body 20. The first partial section 23 of the articulation section 22 of the first transmission gear 11 is formed by the base body 20 of the first transmission gear 11 itself, while the second articulation section 24 is formed by the end section of the inner ring 16 of the rotary bearing 15 which projects into the base body 20. The articulation section 22 of the first transmission gear 11 contacts a corresponding partially spherically and convexly curved articulation section 26 of the transmission nut 4 with the interposition of a two-part sliding bearing layer 25, which is in the form of two separate components made of plastic, wherein the articulation section 26 of the transmission nut 4 likewise has a first partial section 27 and a second partial section 28, which contact the corresponding partial sections 23, 24 of the articulation section 22 of the first transmission gear 11 (indirectly).

The drive nut 4 is arranged partially, in particular with the entire articulation section 26, inside the first drive gear 11 and partially inside the rotary bearing 15, that is to say also inside the outer ring 17 of the rotary bearing 15, forming a defined radial play, wherein the radial play is dimensioned so large that contact between the drive nut 4 and the inner ring 16 of the rotary bearing 15 is avoided in the case of the pivot angle of the drive nut 4 which is expected during operation of the steering system.

Due to the design of the slide bearing layer 25 in the form of two separate components made of plastic, a relevant creep of the plastic of the slide bearing layer 25 can occur during the service life of the steering system due to the relatively large wall thickness of these components. In order to ensure a maximum freedom from play of the steering linkage over the entire service life of the steering system, it is provided, on the one hand, that such creep is already anticipated to the greatest possible extent within the installation range of the steering system. For this purpose, it is provided that, during the assembly of the steering system, the width of the joint gap between the joint sections 22, 26, which gap accommodates the sliding bearing layer 25, is adjusted in such a way that it is significantly smaller than the thickness of the sliding bearing layer 25 in the unloaded state. This (also) leads to a plastic deformation of the sliding-bearing layer 25, which initially, although associated with a relatively large frictional resistance of the pivot bearing, is reduced again relatively quickly due to creep of the plastic of the sliding-bearing layer 25. In this context, it is therefore basically sufficient to compensate for the play which may form during use of the steering system due to wear. In order to ensure this, an elastically deformable spring ring 29 in the form of an elastomer ring is arranged between the hinge sections (22, 26). This spring ring causes a pretensioning force which is also directed in the longitudinal axial direction of the first transmission gear 11 and the transmission nut 4, as a result of which the transmission nut 4 is pressed against the first transmission gear 11 in the direction of the rotary bearing 15, which results in at least the second partial section 28 of the articulation section 26 of the transmission nut 4 bearing against the second partial section 24 of the articulation section 22 of the first transmission gear 11 without play.

In order to transmit the torque from the first transmission gear 11 to the transmission nut 4, a coupling is provided which is formed from an annularly encircling inner toothing 30 of the first transmission gear 11 and an likewise annularly encircling outer toothing 31 of the transmission nut 4 and a toothed intermediate ring 10 made of plastic which interacts with the inner toothing 30 and with the outer toothing 31. For this purpose, the toothed intermediate ring 10 has complementary toothing on its outer and inner sides, respectively. The internal toothing 30 of the first transmission gear 11 and the external toothing 31 of the transmission nut 4 (and thus the corresponding toothing of the toothed intermediate ring 10) are each arranged centrally in the longitudinal axis in each case on the two partial sections 23, 24 of the associated articulation section 22, 26: 27. 28, respectively. Furthermore, the teeth of these

toothing arrangements

30, 31 are oriented parallel to the longitudinal axis 3 of the drive nut 4 or the longitudinal axis 32 of the first drive gear 11. Furthermore, the tooth tips of the external tooth section 31 of the drive nut 4 have a curved course, in order to construct a curved tooth coupling which does not impede the pivoting of the drive nut 4 relative to the first drive gear 11. The toothed intermediate ring 10 is formed integrally and materially in one piece with the part of the sliding bearing layer 25 which is arranged between the respective first partial sections 23, 27 of the hinge sections 22, 26. The toothed intermediate ring 10 thus likewise forms part of the sliding bearing layer 25. This ensures a low-friction pivotable mobility of the pivot joint.

Claims

1. Steering system with a steering rod (2) mounted in a housing (1) so as to be longitudinally movable, and with a steering motor (5) which acts on the steering rod (2) via a ball screw drive (6), for which purpose the steering rod (2) forms a ball circulation thread (7) which interacts via a spherical transmission element (8) with a transmission nut (4) which can be driven by the steering motor (5), wherein the transmission nut (4) is mounted rotatably in the housing (1) by means of a bearing assembly, and wherein a transmission gear (11) of a traction means transmission is connected in a tilt-proof manner to an inner ring (16) of a rotary bearing (15) of the bearing assembly, via which the drive power of the steering motor (5) can be transmitted to the transmission nut (4), and wherein the drive nut (4) is mounted on the drive gear (11) so as to be pivotable about a pivot axis oriented perpendicularly to the longitudinal axis (3) of the steering rod (2), for which purpose the drive nut (4) has a curved articulation section (26), which curved articulation section (26) interacts with a curved articulation section (22) formed at least in part by the drive gear (11) to form a pivot bearing, characterized by an elastically deformable spring ring (29) arranged between the articulation sections (22, 26).

2. Steering system according to claim 1, characterized in that a sliding bearing layer (25) is arranged between the articulation sections (22, 26).

3. Steering system according to claim 2, characterized in that the sliding bearing layer (25) is constructed as a separate component and/or from plastic.

4. Steering system according to one of the preceding claims, characterized in that the first partial section (23) of the articulation section (22) of the transmission gear (11) and the base body (20) of the transmission gear (11) are constructed in one piece, which base body has a functional surface which contacts a traction means of the traction means transmission.

5. Steering system according to any one of the preceding claims, characterized in that the transmission gear (11) is configured as a transmission ring gear and the articulation section (26) of the transmission nut (4) is arranged at least partially inside the transmission gear (11).

6. Steering system according to any of the preceding claims, characterized in that the transmission gear (11) is connected with a transmission nut (4) torque-transferring by means of a coupling.

7. Steering system according to claim 6, characterized in that the coupling comprises a toothing (30) of the transmission gear (11) and a toothing (31) of the transmission nut (4), the toothings (30) and (31) engaging into each other.

8. Steering system according to claim 7, characterized in that the sliding bearing layer/layers (25) is/are also arranged between the teeth (30, 31).

9. The steering system according to one of claims 6 to 8, characterized in that the coupling is arranged between the first partial section (27) and the second partial section (28) of the articulation section (26) of the drive nut (4) and/or between the first partial section (23) and the second partial section (24) of the articulation section (22) of the drive gear (11).

10. A method for assembling a steering system according to claim 2 or any one of the claims dependent on claim 2, characterized by adjusting the width of the articulation gap which is located between the articulation sections (22, 26) and which accommodates the sliding bearing layer (25), said width being smaller than the thickness of the sliding bearing layer (25) in the unloaded state.